Grandma in Basement? CAN ANYONE HELP?

I don't know if this is the right movie even but.....I was never able to find anything that fit my description to this- where a little girl went downstairs in a pitch black basement and saw an old woman in a rocking chair. I think she was like "grandma,grandma?" The Chair seemed to be floating (but that could just be how I remembered it). Also it seemed like the grandma was doing something, like knitting or on some glowing phone? All I know for sure is the basement was absolutely pitch black other than the glowingness that seemed to accompany this strange woman. And also she was directly at the bottom of what seemed like a fairly long staircase. And she was facing away from the stairs towards the dark and not the open door that this little girl opened from the top of the stairs.
I am looking for something with this description if anybody knows it? An episode of some show, movie? The time period would mostly fit into the 80's era of shows. It could probably be a show or movie filmed in late 70's to maybe 1988? I reasearched a few shows last year, such as the Electric Grandma-didn't seem to fit though. And I also tried to look up episodes from classic cult shows of the 80's such as Twilight Zone, Amazing Stories. It was hard because there are plenty of these type shows in the 80's and I am unsure of the type of show also the description-name of episode? Thanks if anyone can help!!!!